Vaccination Against ’Flu “Not Practical Proposition”

Press, Volume CI, Issue 29913, 29 August 1962, Page 15

Vaccination Against ’Flu “Not Practical Proposition”

Lives can be saved during an influenza epidemic by vaccinating those particularly at

risk—persons with chronic diseases of the chest and certain chronic heart conditions, who are in considerable dancer of getting pneumonia and dying, according to Professor C. H Stuart-Harris. Sir G-iorge Franklin Professor of Medicine at the University, of Sheffield, who is visiting New Zealand as the 1952 ’ Sims Commonwealth Travel-I ling Professor. He said in Christchurch last night that the British Ministry of Health had recently approved free vaccination for this group General vaccination of whole populations against influenza was not a practical proposition. To be of maximum value it had to be given immediately before an epidemic. as the disease spread too quickly for vaccine to damp down the epidemic once it was under' way; but there was no known means of predicting an outbreak. Another difficulty was that the viruses causing the disease were “wily.” and continually changing to outwit the body's defensive mechanisms. Professor Stuart-Har-ris said. Sometimes the changes were very small, and in such cases vaccine made from the old strain was still potent against the new; but every 10 years or so a major changes occurred which rendered previous vaccines useless. Two Distinct Types Thev position was complicated by the existence of two distinct types of influenza virus. Type A and Type B The diseases resulting from the two virus types were almost indistinguishable. but vaccines and other treatments against one type would not necessarily be effective against the other. Type A had its last major change in 1957, when Asian influenza appeared; the last considerable change in Type B in England was observed in 1959. "It is probably this 1959 variety of Type B that is biting you people now, al-

though 1 understand that Type A has also been isolated here,” he said. In one way. New Zealand was fortunate in having both types in the one epidemic, as the country would probably now be free of influenza epidemics from either type of virus for at least two years-

Asked whether he thought a cure for influenza—as distinct from a protection against it—was likely to be found in the near future. Profesor Stuart-Harris said he believed that in the next few years substances would be found potent enough to limit the growth of influenza virus. Indeed, claims were being made by an overseas drug firm that a cure was near, and several substances were known which would check the multiplication of the virus in the test-tube. Before any drug could be accepted as satisfactory for general use against the virus in the human b'dy. however, widespread and exhaustive olin it al trials would have to be undertaken to reveal any possible dangers of that drug as well as its protective value. "We have had too

many instances of drugs being released without enough research into their possible side-effects.’’ he commented. Although no drug was widely accepted as being useful against the influenza virus as such, much progress had been made against pneumonic complications and a tremendous reduction had been made over the last few years in the number of deaths indirectly caused by influenza. There was a basic mystery about influenza in that noone knew where it went between epidemics, nor how it managed to change its structure in order to avoid the succession of defences put up by the human body. Some organisms were known to change by a mutation of tiheir germ-material, but that did not seem the explanation in the case of influenza viruses, since by the laws of chance a mutation was immeasurably more likely to occur in the middle of an epidemic, when virus multiplication was at its peak, than when the virus was dormant.

“Some scientists very close to this problem believe that the various strains of virus are already in existence in the reservoir, waiting their chance to break out,” said Professor Stuart-Harris. This would help account for the extreme localisation of the source of most world epidemics. Last evening Professor Stuart-Harris, who is a specialist on several virus diseases gave an address on poliomyelitis to city doctors. Today he will lecture and demonstrate at the Christchurch Hospital, and tomorrow and on Friday he will give papers at the scientific meeting of the Royal Australasian College of Surgeons at the Princess Margaret Hospital. On Saturday he will meet registrars from city hospitals. He will leave Christchurch on Monday to return to Britain.